//将两个升序链表合并为一个新的 升序 链表并返回。新链表是通过拼接给定的两个链表的所有节点组成的。 
//
// 
//
// 示例 1： 
// 
// 
//输入：l1 = [1,2,4], l2 = [1,3,4]
//输出：[1,1,2,3,4,4]
// 
//
// 示例 2： 
//
// 
//输入：l1 = [], l2 = []
//输出：[]
// 
//
// 示例 3： 
//
// 
//输入：l1 = [], l2 = [0]
//输出：[0]
// 
//
// 
//
// 提示： 
//
// 
// 两个链表的节点数目范围是 [0, 50] 
// -100 <= Node.val <= 100 
// l1 和 l2 均按 非递减顺序 排列 
// 
//
// Related Topics递归 | 链表 
//
// 👍 3083, 👎 0bug 反馈 | 使用指南 | 更多配套插件 
//
//
//
//


package leetcode.editor.cn;

;

public class MergeTwoSortedLists {
    public static void main(String[] args) {
        Solution solution = new MergeTwoSortedLists().new Solution();

        ListNode list1 = constructor(10);
        consoleListNode(list1, "list1");
        ListNode list2 = constructor(5);
        consoleListNode(list2, "list2");

        ListNode mergeTwoLists = solution.mergeTwoLists(list1, list2);
        consoleListNode(mergeTwoLists, "mergeTwoLists");
    }

    private static void consoleListNode(ListNode listNode, String listNodeName) {
        ListNode cur = listNode;
        System.out.print(listNodeName + ":");
        while (cur != null) {
            System.out.print(cur.val + " ");
            cur = cur.next;
        }
        System.out.println();
    }

    private static ListNode constructor(int i) {
        ListNode tail = null;
        for (int j = i; j > 0; j--) {
            tail = new ListNode(j, tail);
        }
        return tail;
    }


    public static class ListNode {

        private int val;
        private ListNode next;

        public ListNode(int val) {
            this.val = val;
        }

        public ListNode(int val, ListNode next) {
            this.val = val;
            this.next = next;
        }
    }

    //leetcode submit region begin(Prohibit modification and deletion)

    /**
     * Definition for singly-linked list.
     * public class ListNode {
     * int val;
     * ListNode next;
     * ListNode() {}
     * ListNode(int val) { this.val = val; }
     * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
     * }
     */
    class Solution {
        public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
            ListNode dummy = new ListNode(-1), p = dummy;
            ListNode p1 = list1, p2 = list2;

            while (p1 != null && p2 != null) {
                if (p1.val < p2.val) {
                    p.next = p1;
                    p1 = p1.next;
                } else {
                    p.next = p2;
                    p2 = p2.next;
                }
                p = p.next;
            }
            if (p1 != null) {
                p.next = p1;
            }
            if (p2 != null) {
                p.next = p2;
            }
            return dummy.next;
        }
    }
//leetcode submit region end(Prohibit modification and deletion)


}